It is known to drop incendiaries from helicopters and light aircraft for the purposes of forestry management and back burning. One known incendiary is in the form of a small sphere (of approximately 32 mm diameter) of plastics material filled with a quantity of potassium permanganate granules or powder. Each sphere is formed from two hemispheres injection moulded from extruded plastic and subsequently joined together. A small hole is formed in the sphere to allow filling with a volume of potassium permanganate. The hole is then sealed with wax (hot glue). These spheres are usually dropped from a semi-automatic dispenser provided with a hopper for holding a large number of spheres and which feeds the spheres sequentially to a chute where they are injected with a small volume of glycol. The potassium permanganate and glycol react exothermically leading to their mutual combustion.
This combination of incendiary and dispenser have low reliability. This is in part due to difficulties in sequentially feeding the spheres to a chute and then successfully injecting them with glycol. It is not uncommon for the spheres to become jammed in the chute which then requires manual clearing. If the clearing is not performed expeditiously, there is a risk of combustion occurring within the chute itself. Sometimes, to assist in feeding the spheres to the chute, an agitator is provided in the hopper. However the agitator can cause the spheres to simply circulate within the hopper without dropping into the chute. Another reason for the relatively low reliability is the sealing of the holes through which the spheres are initially loaded with potassium permanganate with wax or hot glue. If the spheres are orientated so that the needle injecting the glycol is aligned with the wax or glue, the needle can become blocked and has to be removed and cleaned before further use. Also, sometimes the needle hits the join and crushes the sphere.